Immune Response, Inflammation
Conditions
Keywords
Blueberries, Immunity, Inflammation
Brief summary
This research study will test the effects of Blueberries on immune functions in overweight older men and postmenopausal women
Detailed description
This study will examine the effects of Blueberries on clinically relevant markers of immune function. Eligible and selected participants will be randomized to one of two groups at the baseline clinic visit. The Blueberry group participants will consume blueberries (2 packets of blueberry freeze-dried powder equivalent to 2 cups of fresh blueberries) added to the habitual diet and the Control group participants will abstain from blueberries (with instructions to limit the consumption of other berries and polyphenol rich foods) but otherwise continue their habitual diet. During the study, clinic visits will occur at 4-week intervals (baseline, weeks 4, 8 and 12) for a total of 4 visits at the Loma Linda University Nutrition Research Center. Blood samples taken at baseline and at week 12 will be assayed for changes in immune function and inflammatory markers.
Interventions
DIETARY_SUPPLEMENTBlueberry powder group
Participants in the blueberry powder group will receive freeze dried blueberries in form of a powder
DIETARY_SUPPLEMENTPlacebo powder group
Participants in the placebo powder group will receive an isocaloric placebo powder
Sponsors
Loma Linda University
U.S. Highbush Blueberry Council
Study design
Allocation
RANDOMIZED
Intervention model
PARALLEL
Primary purpose
PREVENTION
Masking
QUADRUPLE (Subject, Caregiver, Investigator, Outcomes Assessor)
Masking description
The investigator, participant, care provider, outcomes assessor will not be aware of which participant is in which arm
Intervention model description
This will be a parallel, free-living, randomized controlled trial, where 52 overweight men and postmenopausal women will be randomized to receive either the freeze dried blueberries or a placebo powder
Eligibility
Sex/Gender
ALL
Age
50 Years to 70 Years
Healthy volunteers
Yes
Inclusion criteria
1. Older men and post-menopausal women aged 50-70 year 2. Have BMI of 25-32 3. Able to commute to Loma Linda University 4. Consuming a typical American Diet low in polyphenols
Exclusion criteria
1. Intolerance or allergy to Blueberries 2. Regular intake of Blueberries and other berried (\>2 ounces/week) 3. Immune system insufficiency or disease 4. Using immune boosting supplements 5. Exposure to antibiotics and corticoids immediately prior to study 6. Uncontrolled chronic diseases and relevant psychiatric illness, including major depression 7. Flu vaccination and or Covid Vaccination less than 3 months ago from the start of the study
Design outcomes
Primary
| Measure | Time frame | Description |
|---|---|---|
| changes in lymphocyte populations | baseline to 12 weeks | Immunophenotyping will be performed by flow cytometry to measure the number of T helper, T cytotoxic, Naïve and memory cells and B cells |
| changes in cytokine production | baseline to 12 weeks | PBMC cells will be separated from blood, activated and cultured using phytohemagglutinin (PHA). Inflammatory cytokine production will be measured in the resulting supernatant using ELISA |
| changes in natural killer (NK) cell activity | baseline to 12 weeks | The NK degranulation assay will be performed on blood samples. The test will be conducted using a modified flow cytometry method that measures the expression of CD107a |
| changes in serum inflammatory cytokine concentration | baseline to 12 weeks | Changes in the concentrations of the inflammatory cytokines will be performed on serum using enzyme-linked immunoassay (ELISA) |
| changes in complete blood count (CBC) | baseline to 12 weeks | changes in the complete blood count will be performed on whole blood with the use of an automated hematology analyzer at a certified clinical facility |
Countries
United States
Contacts
PRINCIPAL_INVESTIGATORJoan Sabate, DrPH
Loma Linda University
PRINCIPAL_INVESTIGATORSujatha Rajaram, PhD
Loma Linda University
Outcome results
None listed